Physics N Math Flashcards
Difference between scientific and engineering notation
Scientific base 1 to 10 exponent also base 10 ie 5 × 10^25
Eng base 1 to 1000 exponent base 10 BUT exponent multiple of 3
976 × 10^6
Easiest way to divide a fraction?
Cross multiply(keep, switch, flip)
- keep 1st fraction
- switch to multiply
- flip 2nd fraction
2/5 + 3/7
29/35
2/3 × 15/16 =
30/48 (5/8)
Is 3:2 equivalent to 7069:4712?
3/2 = 1.5
7069/4712 =1.5002
So yes
% change =
(Final amount- initial amount/initial amount ) ×100
A (math) term is:
Any variable you separate with a +,-,or = sign
A factor(math ) is
Any variable you separate with a × or ÷
Can be implied like 4ab.
The 4 a and b are all factors
Number that describes growth?
How is it set up in the calc?
2.71828
E^x
At 360 degrees (circle) how many radians
2 pi
At 180 degrees( circle) how many radians
1 pi
If 2 angles add upto 180 they are?
90 they are?
180 = supplementary
90 = complimentary
X= sin 25.3 degrees
Side length 15
Find x
15
Sin
25.3
X = 6.41036
Cos A = .8346
Find A
2nd + cos (0.8346)
A = 33.4257
If a full tank is .5m high, liquid density is 998.2 and gravity is 9.81
What is the kpa?
4.896
Def hydrostatic pressure
Pressure developed by a column of liquid
Newtons 1st law
Object in motion stays in motion and object at rest stays at rest till acted on by an equal or greater force
Newtons 2nd law
The more mass the less accelerate, the harder you push the more accelerates
Newtons 3rd law
For every action there is an equal and opposite reaction
Distance def:
Symbol
The total length of the path an object follows
d
- Displacement def:
- Symbol?
The straight line distance and direction from an objects starting point to its final position
d with line over
V = d/t stands for
Average speed
Distance = speed / time
Average velocity
Displacement = velocity/time
A = Vf - Vo / t stands for
A = acceleration
Vf = final velocity
Vo = initial velocity
T = time
Velocity is speeding up if
A = + and v = +
Or
A = - and v = -
g =
Sooo
-9.8 m/s^2
So always - on velocity
Tension def:
Force through a “rope”
V = VoT + .5 at^2 is for
Velocity as a unit of time
V = Vo + at is for
How far have I gone in a straight line as a unit of time?
V^2 = Vo^2 + 2ax is for
Velocity as a function of distance
3 1lb (1 inch ^2) boxes staked on top of each other
Force?
Pressure?
F = 3lbf
P = 3lbf/in^2
3 1 lb (1 inch ^2)boxes side by side
Force?
Pressure?
F = 3 life
P = 1 lbf/in^2
A winch lifts a 2 kg weight up 4.5 m
What is the output of the winch
W = f x d
W = (2kg × 9.81 m/s^2) x 4.5
W = 19.62 x 4.5
W = 88.29 N
Def work
Units
W = applied force x distance
U = 1 Joule ( 1N force through 1M displacement)
Def power
Units
Scalar rate of doing work.
P = W/t unit J/s
1 J/s = 1 watt
A truck is driving down a road ar 10000N force. How much work in Mega joules in 100m of road
W= force x distance
W= 10000 × 100
W= 1000000 N
W = 1 MN
Ek = 1/2 mv^2 is for
Kinetic energy
Ep= mgh is for
Gravitational potential energy
Pressure triangle vs ohms law
F = V
P = I
A = R
Def : energy
The CAPACITY to do work
Def : energy
The CAPACITY to do work
Ep = 1/2 kx^2 is and is for
Spring potential
K = spring constant in n/m
X = distance stretched/compressed
In m
F = k x is and is for
Hooks law
Force to stretch or compensate a spring fully
K = spring const
X = distance
For calculations with F ex( w = f×d)
What must you do
Remember F = mass x acceleration
V = root (2Ek/m) is for
Velocity from potential energy
Ek = 1/2m v^2 formula
Element def
Cannot break down by chemical means to a simpler substance
Compounds def
Can break down to simpler substances. Contain 2 or more elements
A pipe reduces from(a) 34 cm to(b) 20 cm.
The flow rate at a is 1 m/s. What is it at b?
D1 V1 = D2V2
34 cm^2 × 1 m/s = 20 cm^2 × V2
34^2 / 20^2 = 20^2 × V2
1156/400 = V2
2.89 m/s = V2
Total energy at point 1 is = to point 2 (assuming no friction losses) is _____ equation
Bernoullis
Cohesion is
Attraction between molecules of the same type
Adhesion is
Attraction of molecules of a different type
Intermolecular forces
Attraction / repulsion between neighboring molecules (weak)
Intra molecular
Keep a molecule together (strong)
Density is _____ of _____
Formula
Inverse of specific gravity
P = Mass/Volume
Vg = Volume/Mass formula for
Specific gravity
P = Fg/a is for
Hydrostatic pressure
Pliguid = pgh
Pressure at any depth
p= density
g= gravity
h= depth
Force on an object that keeps it from sinking is
Apparent weight
Reynolds # below 2000 is
Above 4000
Between
Above : turbulent
Below : laminar
Between: transitional
Fb = (Pr) × (g) × (Vd) is
Buoyant force
Pr : displaced fluid density
g : gravity
Vd : displaced fluid volume
🔺️L = a L 🔺️ T or aL0( Tf-To ) is and is for
Linear expansion
🔺️ L = change in length
A = coefficient
L0 = original length
🔺️ T = temp change
Tf final temp
To original
What is latent heat of fusion
The amount of energy required to change a substance from its solid phase to liquid at its melting point without a change in temp
With an incline plane it takes the same amount of energy to push it up as
Lifting straight up
MA = d1/d2 is
MA : mechanical advantage
D1: distance 1 ( whole thing)
D2: effort arm
MA difference between load ropes and effort ropes
Load support (up)
Effort ropes actually pulling
If pulling up on a pull then the pull rope is also a load rope
Volume of a sphere
(4/3) pi × r^2
If using an axle to lift a bucket of water which is the load , which is the effort
Bucket = load
Axle/fulcrum = effort
If there are 5 ropes on pulleys and 1 pull rope. You lift a load 20 feet how much rope do you pull?
100 feet
A bellows is pushing up w 100n force 1.5 m down a fulcrum. Another bellows is 1 m further down pushing up how much force to equal
100 × 1.5 = X × 2.5
= 60 n
Difference between gauge pressure and absolute ( formula)
P gauge = P abs - P atm
P = Po = pgh is for
Absolute pressure
